A pants-type disposable diaper includes a pair of strip projecting parts projecting laterally from a line of connection between front and rear parts located respectively on the belly and back sides of a wearer, a first waist elastic member joined to a first waist region that is an upper part of a waist region extending along a waist opening, and a second waist elastic member joined to a second waist region that is a lower part of the waist region. In a state in which an outer covering sheet is elongated in a right-left direction, a first unit contractile force that is a contractile force in the right-left direction per unit width of the first waist region in an up-down direction is smaller than a second unit contractile force in the second waist region.